Local oscillation routing plan applicable to a multiple rf band rf mimo transceiver

ABSTRACT

Local oscillation circuitry for use in an RF transceiver Integrated Circuit (IC) includes local oscillation generation circuitry operable to produce a local oscillation and local oscillation distribution circuitry. The local oscillation distribution circuitry includes a splitting circuit, a first distribution portion, and a second distribution portion. The splitting circuit receives the local oscillation and produces multiple copies of the local oscillation. The first distribution portion produces a first local oscillation corresponding to a first RF band and a second local oscillation corresponding to a second RF band based and to provide the first local oscillation and the second local oscillation to a first RF transceiver group. The second distribution portion produces a first local oscillation and a second local oscillation and provides the first local oscillation and the second local oscillation to the second RF transceiver group.

CROSS REFERENCES TO RELATED APPLICATIONS

This is a continuation of U.S. Utility application Ser. No. 11/173,043filed Jul. 1, 2005, co-pending, which claims priority to U.S.Provisional Patent Application Ser. No. 60/668,050, filed Apr. 4, 2005,both of which are incorporated herein by reference in their entirety forall purposes.

BACKGROUND OF THE INVENTION

1. Technical Field of the Invention

This invention relates generally to communication circuitry and moreparticularly to radio frequency integrated circuits that may be usedwithin a wireless communication device.

2. Description of Related Art

Communication systems are known to support wireless and wire linedcommunications between wireless and/or wire lined communication devices.Such communication systems range from national and/or internationalcellular telephone systems to the Internet to point-to-point in-homewireless networks. Each type of communication system is constructed, andhence operates, in accordance with one or more communication standards.For instance, wireless communication systems may operate in accordancewith one or more standards including, but not limited to, IEEE 802.11(Wireless Local Area Networks “WLANs”), Bluetooth (Wireless PersonalArea Networks), advanced mobile phone services (AMPS), digital AMPS,global system for mobile communications (GSM), code division multipleaccess (CDMA), time division multiple access (TDMA), frequency divisionmultiple access (FDMA), local multi-point distribution systems (LMDS),multi-channel-multi-point distribution systems (MMDS), and/or variationsthereof.

Depending on the type of wireless communication system, a wirelesscommunication device, such as a cellular telephone, two-way radio,personal digital assistant (PDA), personal computer (PC), laptopcomputer, home entertainment equipment, et cetera communicates directlyor indirectly with other wireless communication devices. For directcommunications (also known as point-to-point communications), theparticipating wireless communication devices tune their receivers andtransmitters to the same channel or channels (e.g., one of the pluralityof radio frequency (RF) carriers of the wireless communication system)and communicate over that channel(s). For indirect wirelesscommunications, each wireless communication device communicates directlywith an associated base station (e.g., for cellular services) and/or anassociated access point (e.g., for an in-home or in-building wirelessnetwork) via an assigned channel. To complete a communication connectionbetween the wireless communication devices, the associated base stationsand/or associated access points communicate with each other directly,via a system controller, via the public switch telephone network, viathe Internet, and/or via some other wide area network.

For each wireless communication device to participate in wirelesscommunications, it includes a built-in radio transceiver (i.e., receiverand transmitter) or is coupled to an associated radio transceiver (e.g.,a station for in-home and/or in-building wireless communicationnetworks, RF modem, etc.). As is known, the transmitter includes a datamodulation stage, one or more intermediate frequency stages, and a poweramplifier. The data modulation stage converts raw data into basebandsignals in accordance with a particular wireless communication standard.The one or more intermediate frequency stages mix the baseband signalswith one or more local oscillations to produce RF signals. The poweramplifier amplifies the RF signals prior to transmission via an antenna.

As is also known, the receiver is coupled to the antenna and includes alow noise amplifier, one or more intermediate frequency stages, afiltering stage, and a data recovery stage. The low noise amplifierreceives inbound RF signals via the antenna and amplifies then. The oneor more intermediate frequency stages mix the amplified RF signals withone or more local oscillations to convert the amplified RF signal intobaseband signals or intermediate frequency (IF) signals. The filteringstage filters the baseband signals or the IF signals to attenuateunwanted out of band signals to produce filtered signals. The datarecovery stage recovers raw data from the filtered signals in accordancewith the particular wireless communication standard.

In many wireless communication systems, it is desirable to operate inmultiple RF bands. For example, the IEEE 802.11 covers operations inboth the 2.4 GHz band and the 5 GHz band. Requirements for suchoperation call for operating in different of these RF bands closely intime. Thus, an RF transceiver supporting such operations must be able totransition from one of these bands to another in short order.Constructing an RF transceiver to support multiple RF band operations isa difficult task from many perspectives. Currently developing operatingstandards will require Multiple Input Multiple Output (MIMO) operationsin which multiple receivers or transmitters of an RF transceiver operatesimultaneously in a common band. Therefore, a need exists forimprovements in the construct of multiple RF band transceivers.

BRIEF SUMMARY OF THE INVENTION

The present invention is directed to apparatus and methods of operationthat are further described in the following Brief Description of theDrawings, the Detailed Description of the Invention, and the claims.Other features and advantages of the present invention will becomeapparent from the following detailed description of the invention madewith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

FIG. 1 is a schematic block diagram illustrating a wirelesscommunication system in accordance with the present invention;

FIG. 2 is a schematic block diagram illustrating a wirelesscommunication device in accordance with the present invention;

FIG. 3 is a schematic block diagram illustrating another wirelesscommunication device in accordance with the present invention;

FIG. 4 is a schematic block diagram illustrating a Radio Frequency (RF)transceiver Integrated Circuit (IC) in accordance with the presentinvention;

FIG. 5 is a schematic block diagram illustrating a portion of the RFtransceiver IC of FIG. 4 in accordance with one embodiment of thepresent invention;

FIG. 6 is a schematic block diagram illustrating a portion of the RFtransceiver IC of FIG. 4 in accordance with another embodiment of thepresent invention;

FIG. 7 is a schematic block diagram illustrating a portion of an RFtransceiver IC or multiple RF transceiver ICs in accordance with stillanother embodiment of the present invention;

FIG. 8 is a schematic block diagram illustrating a portion of an RFtransceiver IC or multiple RF transceiver ICs in accordance with yetanother embodiment of the present invention;

FIG. 9 is a schematic block diagram illustrating another RF transceiverIC in accordance with an embodiment of the present invention; and

FIG. 10 is a schematic block diagram illustrating a portion of an RFtransceiver IC or multiple.

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 is a schematic block diagram illustrating a communication system5 that includes basic service set (BSS) areas 7 and 9, an independentbasic service set (IBSS) 11, and a network hardware device 15. Each ofthe BSS areas 7 and 9 include a base station and/or access point 17, 19and a plurality of wireless communication devices 21-23, 25-31. The IBSS11 includes a plurality of wireless communication devices 33-37. Each ofthe wireless communication devices 21-37 may be laptop host computers 21and 25, personal digital assistant hosts 23 and 29, personal computerhosts 31 and 33, and/or cellular telephone hosts 27 and 35.

The base stations or access points 17 and 19 are operably coupled to thenetwork hardware 15 via local area network connections 39 and 43. Thenetwork hardware 15, which may be a router, switch, bridge, modem,system controller, et cetera, provides a wide area network connection 41for the communication system 5. Each of the base stations or accesspoints 17, 19 has an associated antenna or antenna array to communicatewith the wireless communication devices in its area. Typically, thewireless communication devices register with a particular base stationor access point 17, 19 to receive services from the communication system5. For direct connections (i.e., point-to-point communications) withinIBSS 11, wireless communication devices 33-37 communicate directly viaan allocated channel.

Typically, base stations are used for cellular telephone systems andlike-type systems, while access points are used for in-home orin-building wireless networks. Regardless of the particular type ofcommunication system, each wireless communication device includes abuilt-in radio transceiver and/or is coupled to a radio transceiver tofacilitate direct and/or in-direct wireless communications within thecommunication system 5.

FIG. 2 is a schematic block diagram illustrating a wirelesscommunication device that includes a host device 18-32 and an associatedradio 60. For cellular telephone hosts, the radio 60 is a built-incomponent. For personal digital assistants hosts, laptop hosts, and/orpersonal computer hosts, the radio 60 may be built-in or an externallycoupled component.

As illustrated, the host device 18-32 includes at least a processingmodule 50, memory 52, radio interface 54, input interface 58, and outputinterface 56. The processing module 50 and memory 52 execute thecorresponding instructions that are typically done by the host device.For example, for a cellular telephone host device, the processing module50 performs the corresponding communication functions in accordance witha particular cellular telephone standard.

The radio interface 54 allows data to be received from and sent to theradio 60. For data received from the radio 60 (e.g., inbound data), theradio interface 54 provides the data to the processing module 50 forfurther processing and/or routing to the output interface 56. The outputinterface 56 provides connectivity to an output display device such as adisplay, monitor, speakers, et cetera such that the received data may bedisplayed. The radio interface 54 also provides data from the processingmodule 50 to the radio 60. The processing module 50 may receive theoutbound data from an input device such as a keyboard, keypad,microphone, et cetera via the input interface 58 or generate the dataitself. For data received via the input interface 58, the processingmodule 50 may perform a corresponding host function on the data and/orroute it to the radio 60 via the radio interface 54.

Radio 60 includes a host interface 62, digital receiver processingmodule 64, analog-to-digital converter 66, filtering/gain module 68,down conversion module 70, low noise amplifier 72, local oscillationmodule 74, memory 75, digital transmitter processing module 76,digital-to-analog converter 78, filtering/gain module 80, up-conversionmodule 82, power amplifier 84, and an antenna 86. The antenna 86 may bea single antenna that is shared by the transmit and receive paths or mayinclude separate antennas for the transmit path and receive path. Theantenna implementation will depend on the particular standard to whichthe wireless communication device is compliant.

The digital receiver processing module 64 and the digital transmitterprocessing module 76, in combination with operational instructionsstored in memory 75, execute digital receiver functions and digitaltransmitter functions, respectively. The digital receiver functionsinclude, but are not limited to, digital intermediate frequency tobaseband conversion, demodulation, constellation demapping, decoding,and/or descrambling. The digital transmitter functions include, but arenot limited to, scrambling, encoding, constellation mapping, modulation,and/or digital baseband to IF conversion. The digital receiver andtransmitter processing modules 64 and 76 may be implemented using ashared processing device, individual processing devices, or a pluralityof processing devices. Such a processing device may be a microprocessor,micro-controller, digital signal processor, microcomputer, centralprocessing unit, field programmable gate array, programmable logicdevice, state machine, logic circuitry, analog circuitry, digitalcircuitry, and/or any device that manipulates signals (analog and/ordigital) based on operational instructions. The memory 75 may be asingle memory device or a plurality of memory devices. Such a memorydevice may be a read-only memory, random access memory, volatile memory,non-volatile memory, static memory, dynamic memory, flash memory, and/orany device that stores digital information. Note that when theprocessing module 64 and/or 76 implements one or more of its functionsvia a state machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory storing the corresponding operational instructionsis embedded with the circuitry comprising the state machine, analogcircuitry, digital circuitry, and/or logic circuitry.

In operation, the radio 60 receives outbound data 94 from the hostdevice via the host interface 62. The host interface 62 routes theoutbound data 94 to the digital transmitter processing module 76, whichprocesses the outbound data 94 in accordance with a particular wirelesscommunication standard (e.g., IEEE802.11a, IEEE802.11b, IEEE 802.11g,IEEE 802.11n, IEEE 802.15, Bluetooth, et cetera) to produce digitaltransmission formatted data 96. The digital transmission formatted data96 will be a digital base-band signal or a digital low IF signal, wherethe low IF will be in the frequency range of zero to a few megahertz.

The digital-to-analog converter 78 converts the digital transmissionformatted data 96 from the digital domain to the analog domain. Thefiltering/gain module 80 filters and/or adjusts the gain of the analogsignal prior to providing it to the up-conversion module 82. Theup-conversion module 82 directly converts the analog baseband or low IFsignal into an RF signal based on a transmitter local oscillationprovided by local oscillation module 74. The power amplifier 84amplifies the RF signal to produce outbound RF signal 98. The antenna 86transmits the outbound RF signal 98 to a targeted device such as a basestation, an access point, and/or another wireless communication device.

The radio 60 also receives an inbound RF signal 88 via the antenna 86,which was transmitted by a base station, an access point, or anotherwireless communication device. The antenna 86 provides the inbound RFsignal 88 to the low noise amplifier 72, which amplifies the signal 88to produce an amplified inbound RF signal. The low noise amplifier 72provide the amplified inbound RF signal to the down conversion module70, which directly converts the amplified inbound RF signal into aninbound low IF signal (or baseband signal) based on a receiver localoscillation provided by local oscillation module 74. The down conversionmodule 70 provides the inbound low IF signal (or baseband signal) to thefiltering/gain module 68, which filters and/or adjusts the gain of thesignal before providing it to the analog to digital converter 66.

The analog-to-digital converter 66 converts the filtered inbound low IFsignal (or baseband signal) from the analog domain to the digital domainto produce digital reception formatted data 90. The digital receiverprocessing module 64 decodes, descrambles, demaps, and/or demodulatesthe digital reception formatted data 90 to recapture inbound data 92 inaccordance with the particular wireless communication standard beingimplemented by radio 60. The host interface 62 provides the recapturedinbound data 92 to the host device 18-32 via the radio interface 54.

FIG. 3 is a schematic block diagram illustrating a wirelesscommunication device that includes the host device 18-32 and anassociated radio 60. For cellular telephone hosts, the radio 60 is abuilt-in component. For personal digital assistants hosts, laptop hosts,and/or personal computer hosts, the radio 60 may be built-in or anexternally coupled component.

As illustrated, the host device 18-32 includes a processing module 50,memory 52, radio interface 54, input interface 58, and output interface56. The processing module 50 and memory 52 execute the correspondinginstructions that are typically done by the host device. For example,for a cellular telephone host device, the processing module 50 performsthe corresponding communication functions in accordance with aparticular cellular telephone standard.

The radio interface 54 allows data to be received from and sent to theradio 60. For data received from the radio 60 (e.g., inbound data), theradio interface 54 provides the data to the processing module 50 forfurther processing and/or routing to the output interface 56. The outputinterface 56 provides connectivity to an output display device such as adisplay, monitor, speakers, et cetera such that the received data may bedisplayed. The radio interface 54 also provides data from the processingmodule 50 to the radio 60. The processing module 50 may receive theoutbound data from an input device such as a keyboard, keypad,microphone, et cetera via the input interface 58 or generate the dataitself. For data received via the input interface 58, the processingmodule 50 may perform a corresponding host function on the data and/orroute it to the radio 60 via the radio interface 54.

Radio 60 includes a host interface 62, a baseband processing module 100,memory 65, a plurality of radio frequency (RF) transmitters 106-110, atransmit/receive (T/R) module 114, a plurality of antennas 81-85, aplurality of RF receivers 118-120, a channel bandwidth adjust module 87,and a local oscillation module 74. The baseband processing module 100,in combination with operational instructions stored in memory 65,executes digital receiver functions and digital transmitter functions,respectively. The digital receiver functions may include, but are notlimited to, digital intermediate frequency to baseband conversion,demodulation, constellation demapping, decoding, de-interleaving, fastFourier transform, cyclic prefix removal, space, and time decoding,and/or descrambling. The digital transmitter functions include, but arenot limited to, scrambling, encoding, interleaving, constellationmapping, modulation, inverse fast Fourier transform, cyclic prefixaddition, space and time encoding, and digital baseband to IFconversion. The baseband processing modules 100 may be implemented usingone or more processing devices. Such a processing device may be amicroprocessor, micro-controller, digital signal processor,microcomputer, central processing unit, field programmable gate array,programmable logic device, state machine, logic circuitry, analogcircuitry, digital circuitry, and/or any device that manipulates signals(analog and/or digital) based on operational instructions. The memory 65may be a single memory device or a plurality of memory devices. Such amemory device may be a read-only memory, random access memory, volatilememory, non-volatile memory, static memory, dynamic memory, flashmemory, and/or any device that stores digital information. Note thatwhen the processing module 100 implements one or more of its functionsvia a state machine, analog circuitry, digital circuitry, and/or logiccircuitry, the memory storing the corresponding operational instructionsis embedded with the circuitry comprising the state machine, analogcircuitry, digital circuitry, and/or logic circuitry.

In operation, the radio 60 receives outbound data 94 from the hostdevice via the host interface 62. The baseband processing module 64receives the outbound data 88 and, based on a mode selection signal 102,produces one or more outbound symbol streams 90. The mode selectionsignal 102 will indicate a particular mode of operation that iscompliant with one or more specific modes of the various IEEE 802.11standards. For example, the mode selection signal 102 may indicate afrequency band of 2.4 GHz, a channel bandwidth of 20 or 22 MHz and amaximum bit rate of 54 megabits-per-second. In this general category,the mode selection signal will further indicate a particular rateranging from 1 megabit-per-second to 54 megabits-per-second. Inaddition, the mode selection signal will indicate a particular type ofmodulation, which includes, but is not limited to, Barker CodeModulation, BPSK, QPSK, CCK, 16 QAM, and/or 64 QAM. The mode selectsignal 102 may also include a code rate, a number of coded bits persubcarrier (NBPSC), coded bits per OFDM symbol (NCBPS), and/or data bitsper OFDM symbol (NDBPS). The mode selection signal 102 may also indicatea particular channelization for the corresponding mode that provides achannel number and corresponding center frequency. The mode selectsignal 102 may further indicate a power spectral density mask value anda number of antennas to be initially used for a MIMO communication.

The baseband processing module 100, based on the mode selection signal102 produces one or more outbound symbol streams 104 from the outbounddata 94. For example, if the mode selection signal 102 indicates that asingle transmit antenna is being utilized for the particular mode thathas been selected, the baseband processing module 100 will produce asingle outbound symbol stream 104. Alternatively, if the mode selectsignal 102 indicates 2, 3, or 4 antennas, the baseband processing module100 will produce 2, 3, or 4 outbound symbol streams 104 from theoutbound data 94.

Depending on the number of outbound streams 104 produced by the basebandmodule 10, a corresponding number of the RF transmitters 106-110 will beenabled to convert the outbound symbol streams 104 into outbound RFsignals 112. In general, each of the RF transmitters 106-110 includes adigital filter and upsampling module, a digital to analog conversionmodule, an analog filter module, a frequency up conversion module, apower amplifier, and a radio frequency bandpass filter. The RFtransmitters 106-110 provide the outbound RF signals 112 to thetransmit/receive module 114, which provides each outbound RF signal to acorresponding antenna 81-85.

When the radio 60 is in the receive mode, the transmit/receive module114 receives one or more inbound RF signals 116 via the antennas 81-85and provides them to one or more RF receivers 118-122. The RF receiver118-122, based on settings provided by the channel bandwidth adjustmodule 87, converts the inbound RF signals 116 into a correspondingnumber of inbound symbol streams 124. The number of inbound symbolstreams 124 will correspond to the particular mode in which the data wasreceived. The baseband processing module 100 converts the inbound symbolstreams 124 into inbound data 92, which is provided to the host device18-32 via the host interface 62.

As one of average skill in the art will appreciate, the wirelesscommunication device of FIG. 3 may be implemented using one or moreintegrated circuits. For example, the host device may be implemented onone integrated circuit, the baseband processing module 100 and memory 65may be implemented on a second integrated circuit, and the remainingcomponents of the radio 60, less the antennas 81-85, may be implementedon a third integrated circuit. As an alternate example, the radio 60 maybe implemented on a single integrated circuit. As yet another example,the processing module 50 of the host device and the baseband processingmodule 100 may be a common processing device implemented on a singleintegrated circuit. Further, the memory 52 and memory 65 may beimplemented on a single integrated circuit and/or on the same integratedcircuit as the common processing modules of processing module 50 and thebaseband processing module 100.

FIG. 4 is a schematic block diagram illustrating a Radio Frequency (RF)transceiver Integrated Circuit (IC) in accordance with the presentinvention. The RF transceiver IC 300 includes a first transceiver group302, a second transceiver group 304, a first baseband section 352, asecond baseband section 354, local oscillation generation circuitry 307,and local oscillation distribution circuitry 306. Additional componentsof the RF transceiver IC 300 will be described subsequently herein.

The first baseband section 352 communicatively couples to the first RFtransceiver group 302. Further, the second baseband section 354communicatively couples to the second RF transceiver group 304. Thelocal oscillation generation circuitry 307 generates a local oscillationand couples the local oscillation to the local oscillation distributioncircuitry 306. The local oscillation distribution circuitry 306 operablycouples to the local oscillation generation circuitry 307, to the firstRF transceiver group 302, and to the second RF transceiver group 304.

According to a first aspect to the present invention, the second RFtransceiver group 304 resides in substantial symmetry with the first RFtransceiver group 302 about a center line of symmetry 350 of the RFtransceiver IC 300. As the reader will appreciate, the center line ofsymmetry 350 of the RF transceiver IC 300 is not formed upon the RFtransceiver IC 300 but relates to the layout of the components of the RFtransceiver IC 300. Further, the center line of symmetry 350 of the RFtransceiver IC 300 relates to the substantial but not absolutesymmetrical relationship of the components. Thus, while the first RFtransceiver group 302 and the second RF transceiver group 304 reside insubstantial symmetry with one another about the center line of symmetry350 of the RF transceiver IC 300, such symmetry may not be absolute orprecise but merely substantial. Moreover, the center line of symmetry350 of the RF transceiver IC 300 relates to the symmetrical relationshipof components of the RF transceiver IC 300 and need not reside in acentral location of the RF transceiver IC 300.

The first baseband section 352 includes a first Rx baseband section 320and a first Tx baseband section 324. Further, the second basebandsection 354 includes a second Rx baseband section 322 and a second Txbaseband section 326. According to another aspect of the presentinvention, the second baseband section 354 resides in substantialsymmetry with the first baseband section 352 about the center line ofsymmetry 350 of the RF transceiver IC 300. As was the case with thesymmetry of the first RF transceiver group 302 with respect to thesecond RF transceiver group 304, the symmetry of the baseband section352 and 354 according to the present invention is substantial but maynot be absolute or precise. According to another aspect to thissymmetry, the first Tx baseband section 324 may reside in substantialsymmetry with relation to the second Tx baseband section 326 about thecenter line of symmetry 350 of the RF transceiver IC 300. Further, thefirst Rx baseband section 320 and the second Rx baseband section 322 mayreside in substantial symmetry with each other about the center line ofsymmetry 350 of the RF transceiver IC.

As is apparent upon review of FIG. 4, additional symmetrical and spatialrelationships exist among the functional blocks of the RF transceiver IC300. For example, the local oscillation generation circuitry 307 residessubstantially along the center line of symmetry 350 of the RFtransceiver IC 300. Such location of the local oscillation generationcircuitry 307 in conjunction with the structure of the LO distributioncircuitry 306 facilitates a uniform distribution of local oscillationsignals to the first RF transceiver group 302 and to the second RFtransceiver group 304. When the RF transceiver IC 300 supports MultipleInput Multiple Output (MIMO) communications, the timing and phasealignment of the RF signals produced by the first RF transceiver group302 and the second RF transceiver group 304 is of enhanced importance.Thus, with the structure of the LO distribution circuitry 306 about thecenter line of symmetry 350 of the RF transceiver IC 300, distributionof precisely phase aligned local oscillations is supported.

The additional components of the RF transceiver IC 300 include a PhaseLocked Loop (PLL) 312, PLL buffering circuitry 308, voltage controlledoscillator (VCO)/auto tune circuitry 310, VCO buffering circuitry 311,and crystal oscillator circuitry 314. The VCO/auto tune circuitry 310and the crystal oscillator circuitry 314 operate in conjunction with thePLL 312 to produce inputs to PLL buffering circuitry 308 and the VCObuffering circuitry. The VCO buffering circuitry 311 provides input tothe LO generation circuitry while the PLL buffering circuitry 308provides an input to the PLL 312. The structure and operation ofcircuitry for generating a local oscillation apart from the teachings ofthe present invention is generally known and will not be describedfurther herein.

The RF transceiver IC 300 further includes a digital control processor338, miscellaneous baseband/IF processing 340, miscellaneous circuitry344, miscellaneous baseband IF processing 342 and various input andoutput structures. As the reader will appreciate, the functional blockdiagram of FIG. 4 does not explicitly show connections between thevarious functional blocks of the RF transceiver IC 300. Based upon thefunction and operation of each of these functional blocks, each of thefunctional blocks will be coupled to various other of the functionalblocks to support transmittal of communication signals, control signals,power, and ground between the various functional blocks. As the readerwill appreciate, the connectivity between this various blocks isstraight forward and needs no further description herein.

The RF transceiver IC 300 includes a static digital interface 332 thatresides along an edge of the RF transceiver IC 300 that is substantiallyperpendicular to the center line of symmetry 350 of the RF transceiverIC 300. The RF transceiver IC 300 further includes a first dynamicdigital interface 334 residing along a first edge of the RF transceiverIC 300 that is substantially parallel to the center line of symmetry 350of the RF transceiver IC 300. Further, the RF transceiver IC 300includes a second dynamic digital interface 336 residing along a secondedge of the RF transceiver IC 300 that is substantially parallel to thecenter line of symmetry 350 of the RF transceiver IC 300. The digitalcontrol processor 338 communicatively couples to the static digitalinterface 332 and also resides along the center line of symmetry 350 ofthe RF transceiver IC 300 according to one aspect of the presentinvention.

The RF transceiver IC 300 includes a first baseband analog interface 316that communicatively couples to the first baseband section 352 andresides along a first edge of the RF transceiver IC 300 orientedsubstantially perpendicular to the center line of symmetry 350 of the RFtransceiver IC 300. The RF transceiver IC 300 further includes a secondbaseband analog interface 318 that communicatively couples to the secondbaseband section 354 and resides along the first edge of the RFtransceiver IC 300. Moreover, the RF transceiver IC 300 includes a firstRF analog interface 328 that communicatively couples to the firsttransceiver group 302 and resides along a second edge of the RFtransceiver IC 300 oriented substantially perpendicular to the centerline of symmetry 350 of the RF transceiver IC 300. The second edgeresides opposite the first edge. Finally, the RF transceiver IC 300includes a second analog interface 330 that communicatively couples tothe second transceiver group 304 and resides along the second edge ofthe RF transceiver IC.

FIG. 5 is a schematic block diagram illustrating a portion of the RFtransceiver IC of FIG. 4 in accordance with one embodiment of thepresent invention. With the portion of the RF transceiver FIG. 5, thefirst RF transceiver group 302 includes a first RF band transmitter 506,a first RF band receiver 502, a second RF band transmitter 508, and asecond RF band receiver 504. Likewise, the second transceiver group 304includes a first RF band transmitter 512, a first RF band receiver 516,a second RF band transmitter 510, and a second RF band receiver 514.According to the particular embodiment of FIG. 5, the second RF band isthe 5 GHz band while the first RF band is the 2.4 GHz band. As thereader will appreciate, wireless local area network (WLAN) RFtransceivers are now called upon to operate in both the 5 GHz band andthe 2.4 GHz band. Thus, the RF transceiver IC 300 of the presentinvention supports communications in each of these bands usingrespective transmitters and receivers for each band.

As is illustrated in FIG. 5, the first RF band transmitter 506 of thefirst transceiver group 302 resides in substantial symmetry with thefirst RF band transmitter 512 of the second transceiver group 304 aboutthe center line of symmetry 350 of the RF transceiver IC 300. Further,the second RF band transmitter 508 of the first transceiver group 302resides in substantial symmetry with the second RF band transmitter 510of the second transceiver group 304 about the center line of symmetry350 of the RF transceiver IC. Moreover, the first RF band receiver 502of the first transceiver group 302 resides in substantial symmetry withthe first RF band receiver 516 of the second transceiver group 304 aboutthe center line of symmetry 350 of RF transceiver IC 300. Finally, thesecond RF band receiver 504 of the first RF transceiver group 302resides in substantial symmetry with the second RF band receiver 514 ofthe second RF transceiver group 304 about the center line of symmetry350 of the RF transceiver IC 300.

With the construct of FIG. 5, a sequential order of position of thefirst RF transceiver group 302 components from the center line ofsymmetry 350 of the RF transceiver IC 300 is the second RF bandtransmitter 508, the first RF band transmitter 506, the second RF bandreceiver 504, and the first RF band receiver 502. Further, a sequentialorder of position of the second RF transceiver group 304 components fromthe center line of symmetry 350 of the RF transceiver IC 300 is thesecond RF band transmitter 510, the first RF band transmitter 512, thesecond RF band receiver 514, and the first RF band receiver 516. Withthis construct, the transmitter/receiver pairs in a common band are notadjacent to one another. This provides spatial separation between thesecomponents to reduce coupling of Tx/Rx signals from a transmitter to areceiver in the common band. However, such a construct causes the localoscillation distribution to be slightly more complicated as contrastedto the structure of FIG. 6 which will be described further herein.

Further shown in FIG. 5 are the crystal oscillator 314, the VCO/autotune circuitry 310, the VCO buffering circuitry 311, the PLL 312, thePLL buffering circuitry 308, the local oscillation generation circuitry307, and the local oscillation distribution circuitry 306. According toanother aspect to the present invention, the local oscillationgeneration circuitry 307 is operable to produce a local oscillation atits output. Further, the local oscillation distribution circuitry 306operably couples to the local oscillation generation circuitry 307, tothe first RF transceiver group 302, and to the second RF transceivergroup 304. The local oscillation distribution circuitry 306 includes asplitting circuit 550 that is operable to receive the local oscillationfrom the local oscillation generation circuitry 307 and to producemultiple copies of the local oscillation. In particular, the splittingcircuit 550 includes drivers 518, 528, and 530. The input to of driver530 is the local oscillation produced by the local oscillationgeneration circuitry 307. Further, each of drivers 518 and 528 producesa copy of the local oscillation that is received by driver 530. As isshown, the splitting circuit 550 and the local oscillation generationcircuitry 307 reside substantially along the center line of symmetry 350of the RF transceiver IC 300.

The local oscillation distribution circuitry 306 further includes afirst distribution portion 552 that couples to the splitting circuit 550and that is operable to produce a first local oscillation correspondingto the first RF band based upon local oscillation, to produce a secondlocal oscillation corresponding to the second RF band based upon thelocal oscillation, and to provide both the first local oscillation andthe second local oscillation to the first RF transceiver group 302.Likewise, the second distribution portion 554 couples to the splittingcircuit 550 and is operable to produce both a first local oscillationcorresponding to the first RF band based upon local oscillation and asecond local oscillation corresponding to the second RF band based uponthe local oscillation. Further, the second distribution portion 554 isoperable to provide the first local oscillation and the second localoscillation to the second RF transceiver group 304. By locating thelocal oscillation generation circuitry 307 and the splitting circuitry550 substantially along the center line of symmetry 350 of the RFtransceiver IC 300, and by constructing the splitting circuit 550 withsubstantial symmetry about the center line of symmetry 350 of the RFtransceiver IC 300, multiple copies of the local oscillation are phasematched upon their receipt by each of the first distribution portion 552and the second distribution portion 554.

As is shown, the components of the first distribution portion 552 andthe second distribution portion 554 include drivers and divide-by-twoelements. In particular, the first distribution portion 552 includesdivide-by-two element 520 and drivers 522, 524 and 526. Further, thesecond distribution portion 554 includes divide-by-two element 530 anddrivers 532, 534, and 536. As is illustrated, the components of thefirst distribution portion 552 and the second distribution portion 554reside in substantial symmetry with one another about the center line ofsymmetry 350 of the RF transceiver IC 300. Because both the first RFtransceiver group 302 components and the second RF transceiver group 304components also reside in substantial symmetry about the center line ofsymmetry 350 of the RF transceiver IC, distribution of both the firstlocal oscillation and the second local oscillation to the variouscomponents of these RF transceiver groups 302 and 304 are time and phasealigned.

FIG. 6 is a schematic block diagram illustrating a portion of the RFtransceiver IC of FIG. 4 in accordance with another embodiment of thepresent invention. With the alternate embodiment of FIG. 6, the locationof the components of the RF transceiver group 302 and the second RFtransceiver group 304 differ from the locations of correspondingcomponents of FIG. 5. FIG. 6 does not include components of the localoscillation circuitry other than the LO generation circuitry 307 and theLO distribution circuitry 306. Of course, the reader will appreciatethat the components are not shown for simplicity purposes but arerequired in the full construct of the RF transceiver IC 300.

With the embodiment of FIG. 6, a sequential order of position of thefirst RF transceiver group 302 components from the center line ofsymmetry 350 of the RF transceiver IC 300 is the second RF bandtransmitter 608, the second RF band receiver 606, the first RF bandtransmitter, and the first RF band receiver 602. Likewise, a sequentialorder of position from the center line of symmetry 350 of the RFtransceiver IC of the components of the second RF transceiver group 304is the second RF band transmitter 610, the second RF band receiver 614,the first RF band transmitter 614, and the first RF band receiver 616.As contrasted to the structure of FIG. 6, the transmitter and receiverpairs operating in a common band are adjacent one another instead ofbeing separated by an intervening component.

While the structure may result in additional coupling of a transmitsignal to its adjacent common RF band receiver, the structure allows areduced complexity of local oscillation distribution circuitry 306 to beemployed. As is shown, the local oscillation splitting circuit 650includes drivers 618, 620 and 630. The structure of the splittingcircuit 650 may be identical to that of the splitting circuit 550 ofFIG. 5. The splitting circuit 650 preferably resides along the centerline of symmetry 350 of the RF transceiver IC 300. Further, the drivers620 and 630 may be symmetrically located about the center line ofsymmetry 350 of the RF transceiver IC 300. The first distributionportion 652 includes drivers 622, divide-by-two element 624, driver 626,and driver 628. The second distribution portion 654 includes driver 632,divide-by-two element 634, driver 636, and driver 638. As contrasted tothe structure of the splitting circuit 552 of FIG. 5, the structure ofthe splitting circuit 652 of FIG. 6 is less complicated, may consumeless power, and may require less floor space for construction androuting.

FIG. 7 is a schematic block diagram illustrating a portion of an RFtransceiver IC or multiple RF transceiver ICs in accordance with stillanother embodiment of the present invention. In particular, FIG. 7illustrates how the structure of a first RF transceiver group 302 may beexpanded to include additional RF receivers and RF transmitters. Thestructure of FIG. 7 is similar to the structure of FIG. 5 with regard tothe orientation of RF transmitters and RF receivers in the two RF bands.In such case, the first RF transceiver group 302 includes a second RFband transmitter 702, a first RF band transmitter 704, a RF second bandreceiver 706, a first RF band receiver 708, second RF band transmitter710, a first RF band transmitter 712, a second RF band receiver 714, anda first RF band receiver 716. The components of the first RF transceivergroup 302 may be present on a single RF transceiver IC, with line 717separating a left slice (elements to the left of line 717) and a rightslice (elements to the right of line 717). Alternatively, thesecomponents may be on separate RF transceiver ICs with the separationbetween the ICs along line 717. With the structure of FIG. 7 extended toa second RF transceiver group, complimentary and correspondingtransmitter and receiver components of the second RF transceiver groupmay be included. The structure of the first RF transceiver group 302 andthe second RF transceiver group (not shown) may be substantiallysymmetric about the center line of symmetry 350 of the RF transceiver IC300.

The local oscillation distribution circuitry includes the splittingcircuits 750 and a first distribution portion 752. In such case, thesplitting circuit 750 includes drivers 718, 720, and 722. The firstdistribution portion 752 includes divide-by-two element 724 and drivers726, 728, 730, 732, 736, 738, and 740. When the first RF transceivergroup 302 resides on a single RF transceiver IC, all of the elements ofthe first distribution portion 752 reside on the single RF transceiverIC. However, if the components of the first RF transceiver group 302extend across multiple ICs, the components of the first distributionportion 752 will reside upon multiple RF transceiver ICs with separationat line 716.

FIG. 8 is a schematic block diagram illustrating a portion of an RFtransceiver IC or multiple RF transceiver ICs in accordance with yetanother embodiment of the present invention. The structure of FIG. 8 mayreside on a single RF transceiver IC or upon multiple RF transceiver ICsand generally corresponds to the structure of FIG. 6. When the structureof FIG. 8 resides on a single RF transceiver IC, all of the componentsof the first RF transceiver group 302 reside upon the single RFtransceiver IC with line 817 separating a left slice from a right slice.However, when the components illustrated in FIG. 8 reside on multiple RFtransceiver ICs (e.g., along dividing line 817), some of the componentsof the first RF transceiver group 302 and distribution portion 852reside on a first RF transceiver IC while other components of the firstRF transceiver group 302 and distribution portion 852 reside on a secondRF transceiver IC.

In the construct of FIG. 8, a different ordering of the Tx and Rx blocksof the first RF transceiver group 302 is shown. In such case, the firstRF transceiver group 302 includes a second RF band transmitter 802, asecond RF band receiver 804, a first RF band transmitter 806, a first RFband receiver 808, a second RF band transmitter 810, a second RF bandreceiver 812, a first RF band transmitter 814, and a first RF bandreceiver 816. Also shown in FIG. 8 are local oscillation generationcircuitry 307 and local oscillation distribution circuitry 306. Thelocal oscillation distribution circuitry 306 corresponding to the firstRF transceiver group 302 includes splitting circuit 850 and firstdistribution portion 852. The splitting circuit 850 includes drivers816, 820, 852. The first distribution portion 852 includes drivers 822,826, 830, 832, 836, and 838. The first distribution portion 852 alsoincludes divide by 2 element 824. Of course, since the components shownin FIG. 8 correspond to only one-half of an RF transceiver, a seconddistribution portion (not shown) would reside substantially symmetricabout the center line of symmetry at 350 of the RF transceiver IC.

FIG. 9 is a schematic block diagram illustrating another RF transceiverIC in accordance with an embodiment of the present invention. The RFtransceiver IC illustrated in FIG. 9 extends the principles previouslydescribed with reference to FIGS. 4-8. The RF transceiver IC 900includes a first RF transceiver group 902, a second RF transceiver group904, a third RF transceiver group 906, and a fourth RF transceiver group908. The RF transceiver IC 900 further includes a first baseband section962, a second baseband section 964, a third baseband section 966, and afourth baseband section 968. The first baseband section 962 includes afirst receive baseband section 910 and a first transmit baseband section912. The second baseband section 964 includes a second transmit basebandsection 916 and a second receive baseband section 914. The thirdbaseband section 966 includes a third receive baseband section 918 and athird transmit baseband section 920. The fourth baseband section 968includes a fourth transmit baseband section 922 and a fourth receivebaseband section 924.

The RF transceiver IC 900 of FIG. 9 includes XO/VCO/LO circuitryreferred to jointly as local oscillation generation circuitry 940. TheRF transceiver IC 900 further includes local oscillation distributioncircuitry 942 and local oscillation distribution circuitry 944. Localoscillation distribution circuitry 942 services the first RF transceivergroup 902 and the second RF transceiver group 904. Local oscillationdistribution circuitry 944 services the third RF transceiver group 906and the fourth RF transceiver group 908. Further shown is PLL 938 thatoperates in conjunction with the local oscillation generation circuitry940 to produce at least one local oscillation.

The input and output structure of the RF transceiver IC 900 includes RFanalog interfaces 926, 928, 930, and 932 which service the first RFtransceiver group 902, the second RF transceiver group 904, the third RFtransceiver group 906, and the fourth RF transceiver group 908,respectively. Further included are static digital interface 946, anddynamic digital interfaces 954 and 956. Baseband/IF analog interfaces934 and 936 service the baseband sections 962, 964, 966, and 968 of theRF transceiver IC 900. Because the baseband/IF analog interfaces 934 and936 do not reside along an edge of the RF transceiver IC 900, standardbonding techniques may not be employed. Thus, with this construct, anon-standard lead termination and packaging technique would be employed.

Shown in FIG. 9 are various symmetrical relationships of the componentsof the RF transceiver IC 900. According to one aspect of the teachingsof FIG. 9, the second RF transceiver group 904 resides in substantialsymmetry with the first RF transceiver group 902 about a first centerline of symmetry 950 of the RF transceiver IC 900. According to anotheraspect, the third RF transceiver group 906 resides in substantialsymmetry with the first RF transceiver group 902 about a second centerline at symmetry 952 of the RF transceiver IC 900. The second centerline of symmetry 952 of the RF transceiver IC 900 may be substantiallyperpendicular to the first center line of symmetry 950 of the RFtransceiver IC 900.

According to another aspect of the teachings of FIG. 9, the fourth RFtransceiver group 908 resides in substantial symmetry with the third RFtransceiver group 906 about the first center line of symmetry 950 of theRF transceiver IC 900. Further, the fourth RF transceiver group 908resides in substantial symmetry with the second RF transceiver group 904about the second center line of symmetry 952 of the RF transceiver IC900.

According to other symmetrical relationships of the structure of FIG. 9,the second baseband section 964 resides in substantial symmetry with thefirst baseband section 962 about the first center line of symmetry 950of the RF transceiver IC 900. According to another symmetrical aspect ofthe structure of FIG. 9, the fourth baseband section 968 resides insubstantial symmetry with the third baseband section 966 about the firstcenter line of symmetry 950 of the RF transceiver IC 900. Further, thethird baseband section 966 resides in substantial symmetry with thefirst baseband section 962 about the second center line of symmetry 952of the RF transceiver IC 900. Finally, the fourth baseband section 968resides in substantial symmetry with the second baseband section 964about the second center line of symmetry 952 of the RF transceiver IC900. Such symmetrical relationships of the baseband sections extend tothe component may extend to the components of the baseband sections suchthat the various components of the baseband section would have symmetryas well.

FIG. 10 is a schematic block diagram illustrating a portion of an RFtransceiver IC or multiple RF transceiver ICs in accordance with stillanother embodiment of the present invention. The structure of FIG. 10may reside on a single RF transceiver IC or upon multiple RF transceiverICs and generally corresponds to the structure of FIG. 6. In theconstruct of FIG. 10, a different ordering of the Tx and Rx blocks ofthe first RF transceiver group 302 is shown. In such case, the first RFtransceiver group 302 includes a second RF band transmitter 1002, asecond RF band receiver 1004, a second RF band transmitter 1006, asecond RF band receiver 1008, a first RF band transmitter 1010, a firstRF band receiver 1012, a first RF band transmitter 1014, and a first RFband receiver 1016. Also shown in FIG. 10 are local oscillationgeneration circuitry 307 and local oscillation distribution circuitry306. The local oscillation distribution circuitry 306 corresponding tothe first RF transceiver group 302 includes splitting circuit 1050 andfirst distribution portion 1052. The splitting circuit 1050 includesdrivers 1016, 1020, and 1052. The first distribution portion 1052includes drivers 1022, 1024, 1026, 1028, 1030, and 1032. The firstdistribution portion 1052 also includes divide by 2 element 1034. Ofcourse, since the components shown in FIG. 10 correspond to onlyone-half of an RF transceiver, a second distribution portion (not shown)would reside substantially symmetric about the center line of symmetry350 of the RF transceiver IC.

As one of ordinary skill in the art will appreciate, the term“substantially” or “approximately,” as may be used herein, provides anindustry-accepted tolerance to its corresponding term and/or relativitybetween items. Such an industry-accepted tolerance ranges from less thanone percent to twenty percent and corresponds to, but is not limited to,component values, integrated circuit process variations, temperaturevariations, rise and fall times, and/or thermal noise. Such relativitybetween items ranges from a difference of a few percent to magnitudedifferences. As one of ordinary skill in the art will furtherappreciate, the term “operably coupled”, as may be used herein, includesdirect coupling and indirect coupling via another component, element,circuit, or module where, for indirect coupling, the interveningcomponent, element, circuit, or module does not modify the informationof a signal but may adjust its current level, voltage level, and/orpower level. As one of ordinary skill in the art will also appreciate,inferred coupling (i.e., where one element is coupled to another elementby inference) includes direct and indirect coupling between two elementsin the same manner as “operably coupled.” As one of ordinary skill inthe art will further appreciate, the term “compares favorably,” as maybe used herein, indicates that a comparison between two or moreelements, items, signals, etc., provides a desired relationship. Forexample, when the desired relationship is that signal 1 has a greatermagnitude than signal 2, a favorable comparison may be achieved when themagnitude of signal 1 is greater than that of signal 2 or when themagnitude of signal 2 is less than that of signal 1.

The preceding discussion has presented a phase locked loop with powerdistribution that reduces noise generated by the phase locked loop. Byreducing noise within the phase locked loop, the phase locked loop maybe used within a local oscillation generator to reduce noise therein. Asone of ordinary skill in the art will appreciate, other embodiments maybe derived from the teaching of the present invention without deviatingfrom the scope of the claims.

1. A Radio Frequency (RF) transceiver Integrated Circuit (IC)comprising: a first RF transceiver module that is operable to servicecommunications within at least one RF band; and a second RF transceivermodule that is operable to service communications within the at leastone RF band; local oscillation generation circuitry operable to producea local oscillation; and local oscillation distribution circuitrycoupled to the local oscillation generation circuitry, to the first RFtransceiver module, and to the second RF transceiver module, the localoscillation distribution circuitry comprising: splitting circuitryoperable to receive the local oscillation from the local oscillationgeneration circuitry and to produce multiple copies of the localoscillation; a first distribution portion coupled to the splittingcircuitry and operable to produce a first local oscillationcorresponding to the at least one RF band based upon the localoscillation and to provide the first local oscillation to the first RFtransceiver module; and a second distribution portion coupled to thesplitting circuitry and operable to produce a second local oscillationcorresponding to the at least one RF band based upon the localoscillation and to provide the second local oscillation.
 2. The RFtransceiver of claim 1, wherein the local oscillation generationcircuitry resides substantially along a center line of symmetry of theRF transceiver IC.
 3. The RF transceiver of claim 1, wherein thesplitting circuitry of the local oscillation distribution circuitryresides substantially along a center line of symmetry of the RFtransceiver IC.
 4. The RF transceiver IC of claim 1, wherein the firstdistribution portion and the second distribution portion of the localoscillation distribution circuitry reside in substantial symmetry abouta center line of symmetry of the RF transceiver IC.
 5. The RFtransceiver IC of claim 1, further comprising: a first baseband sectionhaving a first Rx baseband section and a first Tx baseband section; asecond baseband section having a second Rx baseband section and a secondTx baseband section; and wherein the first baseband section and thesecond baseband section reside in substantial symmetry about a centerline of symmetry of the RF transceiver IC.
 6. The RF transceiver IC ofclaim 1, wherein: the first RF transceiver module comprises a first RFband transmitter, a first RF band receiver, a second RF bandtransmitter, and a second RF band receiver; and the second RFtransceiver module comprises a first RF band transmitter, a first RFband receiver, a second RF band transmitter, and a second RF bandreceiver.
 7. The RF transceiver IC of claim 6, wherein: the first RFband transmitter of the first transceiver group resides in substantialsymmetry with the first RF band transmitter of the second transceivergroup about a center line of symmetry of the RF transceiver IC; thesecond RF band transmitter of the first transceiver group resides insubstantial symmetry with the second RF band transmitter of the secondtransceiver group about the center line of symmetry of the RFtransceiver IC; the first RF band receiver of the first transceivergroup resides in substantial symmetry with the first RF band receiver ofthe second transceiver group about the center line of symmetry of the RFtransceiver IC; and the second RF band receiver of the first transceivergroup resides in substantial symmetry with the second RF band receiverof the second transceiver group about the center line of symmetry of theRF transceiver IC.
 8. The RF transceiver IC of claim 7, wherein: asequential order of position of the first transceiver group componentsfrom the center line of symmetry of the RF transceiver IC is the secondRF band transmitter, the first RF band transmitter, the second RF bandreceiver, and the first RF band receiver; and a sequential order ofposition of the second transceiver group components from the center lineof symmetry of the RF transceiver integrated circuit is the second RFband transmitter, the first RF band transmitter, the second RF bandreceiver, and the first RF band receiver.
 9. The RF transceiver IC ofclaim 7, wherein: a sequential order of position of the firsttransceiver group components from the center line of symmetry of the RFtransceiver IC is the second RF band transmitter, the second RF bandreceiver, the first RF band transmitter, and the first RF band receiver;and a sequential order of position from the center line of symmetry ofthe RF transceiver integrated circuit of the second transceiver groupcomponents is the second RF band transmitter, the second RF bandreceiver, the first RF band transmitter, and the first RF band receiver.10. The RF transceiver IC of claim 1, wherein: the first distributionportion of the local oscillation distribution circuitry resides betweena first baseband section and the first RF transceiver module; and thesecond distribution portion of the local oscillation distributioncircuitry further resides between a second baseband section and thesecond RF transceiver module.
 11. The RF transceiver IC of claim 1,wherein: the first RF transceiver module comprises a first RF bandtransmitter and a first RF band receiver; and the second RF transceivermodule comprises a first RF band transmitter and a first RF bandreceiver.
 12. A Radio Frequency (RF) transceiver Integrated Circuit (IC)comprising: a first RF transceiver module that is operable to servicecommunications within at least one RF band; and a second RF transceivermodule that is operable to service communications within the at leastone RF band; local oscillation generation circuitry operable to producea local oscillation; local oscillation splitting circuitry coupled tothe local oscillation generation circuitry and operable to receive thelocal oscillation from the local oscillation generation circuitry and toproduce multiple copies of the local oscillation, the local oscillationsplitting circuitry residing substantially along a center line ofsymmetry of the RF transceiver IC; and local oscillation distributioncircuitry coupled to the local oscillation splitting circuitry andoperable to couple a first local oscillation received from the localoscillation splitting circuitry to the first RF transceiver module andoperable to couple a second local oscillation received from the localoscillation splitting circuitry to the second RF transceiver module. 13.The RF transceiver IC of claim 12, wherein the local oscillationdistribution circuitry comprises: first local oscillation distributioncircuitry operable to couple the first local oscillation received fromthe local oscillation splitting circuitry to the first RF transceivermodule; second local oscillation distribution circuitry operable tocouple the second local oscillation received from the local oscillationsplitting circuitry to the second RF transceiver module; and wherein thefirst local oscillation distribution circuitry and the second localoscillation distribution circuitry reside in substantial symmetry abouta center line of symmetry of the RF transceiver IC.
 14. The RFtransceiver IC of claim 12, wherein the local oscillation generationcircuitry resides substantially along a center line of symmetry of theRF transceiver IC.
 15. The RF transceiver IC of claim 12, wherein thelocal oscillation splitting circuitry resides substantially along acenter line of symmetry of the RF transceiver IC.
 16. The RF transceiverIC of claim 12, further comprising: a first baseband section coupled tothe first RF transceiver module; a second baseband section coupled tothe second RF transceiver module; and wherein the first baseband sectionand the second baseband section reside in substantial symmetry about acenter line of symmetry of the RF transceiver IC.
 17. The RF transceiverIC of claim 17, wherein: a first portion of the local oscillationdistribution circuitry resides between the first baseband section andthe first RF transceiver module; and a second portion of the localoscillation distribution circuitry resides between the second basebandsection and the second RF transceiver module.
 18. The RF transceiver ICof claim 12, wherein: the first RF transceiver module comprises a firstRF band transmitter, a first RF band receiver, a second RF bandtransmitter, and a second RF band receiver; and the second RFtransceiver module comprises a first RF band transmitter, a first RFband receiver, a second RF band transmitter, and a second RF bandreceiver.
 19. The RF transceiver IC of claim 12, wherein: the first RFtransceiver module comprises a first RF band transmitter and a first RFband receiver; and the second RF transceiver module comprises a first RFband transmitter and a first RF band receiver.